Linking Mental Health and the Gut Microbiome

Summary: A new study explores the potential link between the gut microbiome and mental health. Researchers report depression may be influenced by disturbances to gut bacteria, suggesting nutrition and diet, in combination with other strategies, could help treat the disorder.

Source: Frontiers.

Researchers continue to explore the role of the gut microbiome in neurodevelopment and mental health.

Better understanding the gastrointestinal microbiome may help psychiatrists treat mental health disorders such as depression, highlights a review in Frontiers in Psychiatry.

From a psychiatric standpoint, the underlying causes of depression are still not fully understood and depression remains difficult to treat in some cases. Given increasing interest in the role of the microbiome in a range of human health issues, this has led many researchers to also investigate potential links between mental health and the microbiome — specifically the microbial flora of the gut.

“The main idea of our review is that there is strong communication between the gastrointestinal tract and the brain, and that changes to the microbiome-gut-brain axis could be associated with the etiology of different neuropsychiatric disorders such as depression,” says Juan M. Lima-Ojeda, lead author of the review and a physician and researcher at the University of Regensburg, Germany.

Lima-Ojeda and his colleagues reviewed the body of literature on the role of the gut microbiome with a particular emphasis on the connections, or axis, formed between the microbiome, the gut, and the brain. The brain and the gastrointestinal tract are bi-directionally linked through the central nervous system, endocrine system, and immune system, and perturbations to any of these systems can have repercussions across the others, in turn potentially influencing a person’s overall wellbeing.

“This review was motivated by the interest to obtain a better understanding of both the etiology and pathophysiology of the depressive syndrome,” says Lima-Ojeda. “If we want to improve the treatment strategies that we have for our patients, it is necessary to understand this heterogenic neuropsychiatric disorder.”

The MGB axis, including the hypothalamic–pituitary–adrenal (HPA) axis. The MGB axis is a bidirectional system that links the gastrointestinal tract with the brain. It is a complex system characterized by a neuroendocrine–immune communication. The gut microbiome influences the function of the brain by modulation of both immune and endocrine systems, HPA axis, neurotransmitter pathways, and growth factors. Alterations of this network—that includes numerous molecules and cells—may be the basis of pathological processes. NeuroscienceNews.com image is credited to Lima-Ojeda et al./Frontiers in Psychology.

Their findings included evidence of the gut-microbiome’s formation and influence beginning already in the very earliest stages of life in-utero. Some of these publications propose that the interactions between the brain and gut are just as influential, if not possibly more important, during neurodevelopment, suggesting that depressive syndromes might be traced back to imbalances during neurodevelopment.

However, Lima-Ojeda additionally uncovered evidence that depression may also be attributable to disturbances to the gut microbiome at any point during a person’s life, which can be due to stress, diet, and of course medications such as antibiotics. These findings promote the idea that attention to nutrition and diet may be a practical and effective complement to existing strategies for the treatment of depression.

“Our habits — including our diet–are important factors modulating the microbiome-gut-brain axis,” says Lima-Ojeda. “So, an appropriate diet is important for adequate mental health, where an appropriate diet is one that includes vegetables, fruits, whole grains, fish, and enough water.”

About this neuroscience research article

Funding: This research was funded by German Federal Ministry of Education and Research.

Recently, there has been renewed interest in the role played by microbiome in both human health and human disease. A correct equilibrium between the human host and their microorganisms is important for an appropriate physiological function. Extensive research has shown that microbes that inhabit the gastrointestinal tract—or gut microbiota—are involved not only in both nutritive and digestive activities but also in immunological processes. Moreover, the gut microbiome influences both central nervous system and energy homeostasis. An altered gut microbiome has been associated with the pathophysiology of different diseases, including neuropsychiatric disorders. Apparently, both environmental—diet, exposition to antibiotics, and infections—and host-genetic factors have a strong influence on gut microbiome, modulating the risk for neuropsychiatric illness. Also, early life disruption of the microbiome–gut–brain (MGB) axis has been associated with an increased risk of developing depression later in life, suggesting a link between gut microbiome, neurodevelopment, and depression. This review aims to contribute to this growing area of research by exploring the role played by the gut microbiome in neurodevelopment and in the etiology of the depressive syndrome, including nutritional, immunological, and energy homeostasis approaches.

2 Responses

Makes so much sense to the etiology of my personal case of depression.

I’ve had multiple bouts of major depression throughout my life, starting at age 15 as a result of a night of intoxication. Other triggers of depressive episodes have include common colds. But the very most puzzling depressive episode came on spontaneously – I was at a high point in life at age 21, and one morning I woke up in that nasty fog of depression, not having ANY clue what had caused it! The only thing that I can even think of as a possible cause would have been by some kind of neurochemical imbalance caused by my absolutely terrible eating habits – something disrupting the gut microbiome.

I believe that its possible that a link could be involved but the evidence of how much really is this can be attributed to food? I strongly believe that the key factor is genes because people suffred from depression long before food was a problem.